South Main ST over Las Trampas Creek
GoodContra Costa County, California · 0.1 MI S Olympic Blvd · Structure no. 28C0075
- Built
- 1919
- 106 years old, rebuilt 1956
- Condition
- Good
- inspected January 2025
- Type
- Tee Beam
- Concrete Continuous
- Length
- 131 ft
- 5 main spans
- Daily traffic
- 17,700
- 2019 count
- Owner
- City
- City or Municipal Highway Agency
About this bridge
South Main ST over Las Trampas Creek is a concrete continuous tee beam carrying South Main ST over Las Trampas Creek in Contra Costa County, California. It was built in 1919 and reconstructed in 1956, so it is 106 years old, older than the California average of 54.8 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 17,700 vehicles a day, roughly 3% of them trucks, projected to reach 32,820 by 2047. The structure is 131 ft (39.9 m) long and 66 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was South Main ST over Las Trampas Creek built?
It was built in 1919, making it 106 years old in 2025. It was reconstructed in 1956.
What condition is South Main ST over Las Trampas Creek in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in January 2025.
How much traffic does South Main ST over Las Trampas Creek carry?
About 17,700 vehicles per day (2019 count), of which roughly 3% are trucks.
How long is South Main ST over Las Trampas Creek?
The structure is 131 ft (39.9 m) long with a longest span of 28 ft (8.5 m) and a deck 66 ft wide.
Who owns South Main ST over Las Trampas Creek?
It is owned by the City or Municipal Highway Agency.